/**
javadoc
用于被提取生成说明文档

byte
short
int
long
char
boolean
class
接口 interface
变量作用范围 {}
*/

public class Demo
{
	public static void main(String[] args)
	{
		byte b = 3;
		long c = 132213131324l;	//后面加 l
		float d = 2.3f; //后面加 f
		char ch = 'a';
		boolean bl = true;
		bl = false;
		System.out.println("hello world");
		System.out.println(b);
		System.out.println("ab"+5); // + 连接符
	}   
}
